Many investors are undeterred by lenders making it harder for them to get a property loan although some off-the-plan buyers may end up unable to complete their purchase.

A Mortgage Choice survey shows that 54 per cent of potential investors would still go ahead with their plans despite lenders making sweeping changes to their lending policy and pricing.

Many lenders, including most of the major banks, have hiked interest rates on investment property loans in the past week but Mortgage Choice chief executive John Flavell says the majority of investors still view property as a lucrative investment strategy.

"When we asked potential investors whether or not now was a good time to invest, more than 70 per cent said yes, which goes some way to explaining why so many potential investors are not deterred by the spate of pricing and policy changes being made by many of Australia's lenders," he said.

But, Mr Flavell said, the changes did represent a fundamental shift for people who had purchased property off the plan and had their loans approved on the basis of lending policy and pricing at that time.

"There's potentially some issues in relation to people not being able to complete transactions by virtue of the shifting sands," he said.

Smaller mortgage player AMP Bank has temporarily stopped lending to new property investors and has raised rates on its existing loans to landlords by 47 basis points. That's well above Commonwealth Bank, ANZ and Macquarie's 27 percentage point increase.

National Australia Bank hiked variable rates on interest-only home loans - the predominant structure for investors - by 29 basis points, leaving Westpac as the only major bank not to have raised investment loan rates.

Ratings agency Moody's Investors Service expects Westpac, Australia's largest lender to landlords, to follow its peers in repricing its investment mortgage book.

"Increased lending rates are credit positive for the banks because they rebalance their portfolios away from the higher-risk investor and interest-only lending toward safer owner-occupied and principal amortising loans," Moody's vice president Ilya Serov said.